Pressure totalizing device



June 21, 1949. I MARKSON 2,473,717

PRESSURE TOTALI ZING DEVI GE Filed June 22, 1944 W ay/5532mm l I v I 4Patented June 21, 1949 UNITED STATES OFFICE PRESSURE TOTALIZING DEVICEApplication June 22, 1944, Serial No. 541,645

3 Claims. 1

This invention relates to a system for totalizing fluid pressures or thesum or difference of a number of fluid pressures or of derived functionsthereof.

It is among the objects of the invention to provide a weighing system inwhich the fluid flows of fiuid pressure control systems may be added,subtracted or multiplied. The invention will become more apparent from aconsideration of the accompanying drawing constituting a part thereof,in which like reference characters designate like parts, and in whichFig. l is a diagrammatic view illustrating the fluid pressure measuringsystem;

Fig. 2 a top plan view thereof; and

Fig. 3 a diagrammatic view showing a detail the fluid pressure measuringdevice.

In the drawin numeral l designates a weigh beam fulcrumed at 2 andbiased by a coil spring 3 to counteract the weight of the beam and toact as either a zeroizing or a bias spring. A weighing pan 4 issuspended by a link 5 from a fulcrum that is mounted in a notch l at oneend of the weigh beam l. The weigh beam and its load is counteracted bya pneumatic balancer or operator 8 having an air chamber 9 closed at oneend by a diaphragm l and communicating at its upper end with a valvechamber I l leading to a source of air pressure designated by the arrowl2. A valve E3 having a stem l4 rests upon a lug l of diaphragm ill. Thestem [4 also functions as a valve to control the escape of air throughthe orifice id of a fulcrum pin [1 that fits in a notch it of the weighbeam. An indicator i9 is connected. to reflect the air pressures in thecylinder ii.

The fluid pressures are measured and totalized by means of a pluralityof containers 20 mounted on the weigh pan 4 that are connected byflexible conduits 2! to fixed containers 22 which in turn are connectedby conduits 23 to a source of positive or negative air pressure. Theindicator l9 may be set at zero pressure when the system is used fortotalizing positive pressures only, or it may be set to a specifiedpressure, such as 30 pounds, which would be maintained in the chamber 9if negative pressures are to be measured and totalized. In either case,assuming that both positive and negative pressure impulses aretransmitted from the source through conduits 23 to their respectivecontainers 22, the positive pressures will displace the fluid of thechamber to which it is connected through the flexible conduit 2! to itscorresponding container 20 on the weigh pan 4. Any negative pressureswill correspondingly cause a displacement of fluid from its container onthe weigh pan 4 to the outer container 22, and the total change inweight of the fluid in the containers 26 on the weigh pan l will cause adeflection of the weigh beam l in one direction or the other. Assumingthe total pressures of the respective sources are greater than the zerofor which the weigh beam is set, the arm L1 will be deflected downwardlyand L2 lifted which, being in contact with the fulcrum member ll, willlift the latter to unseat valve [3 from its seat [3a, allowing pressurefluid from the source l2 to enter the chamber 9 until the beam I isbalanced to the horizontal position and valve 13 again seats at 53a. Theamount of fluid pressure thus admitted to the chamber 9 is reflected onthe indicator it which is calibrated to give a direct reading of thequantity desired as determined by the total weight on the weigh pan 4.

If there is a decrease in the pressure fluids being weighed, lever armL2 will be. deflected downwardly and fulcrum H which is attached to thediaphragm ID will be lowered, as will also the diaphragm Iii, to expandthe volume of chamber 9 which causes a drop in the pressure reading ofthe gauge l9. If the downward movement of the fulcrum and diaphragm, Hand Ill respectively, is sufliciently great to unseat the valve' stem[4, the air from chamber 9 will vent through the passage It to theatmosphere until the pressure in chamber 9 corresponds to the actualweight on the weigh pan. When the pressure in chamber 9 and the weighton the weigh pan are in balance the device is in equilibrium.

In this manner both positive and negative totals are obtainable becausein either case the balancer 8 always restores the weigh beam I to itsneutral position. That is, if at the zero condition, the bias spring 3is set to give a pressure output of 30 lbs. then the pressure range 30to lbs. might represent positive totals while 30 to zero might representnegative totals on the weigh pan.

A gain 'or loss of weight is therefore proportional to the displacementof the fluid in the containers 2B and 22, which is proportional to thepressure difference at the sources, which is therefore proportional tothe change of registered air pressure.

To express this mathematically, let

AP be the change of pressure on gauge l9, p. s. i.

A be the area of the balancer diaphragm, sq. in.

A3) be the change of applied pressure to chamber AV be the volume offluid displaced by the change in pressure Ago, cu. in.

d=the density of the displaced fluid, pound per cu. in.

Then neglecting the d isity of air, we may say,

AV-d-(varies as) Ap AV'd'L1=AP-A'L2 or since everything is constant butAV, Ago and AP,

AP=kAp For any number pairs of chambers such as and 22, the samerelation holds, so that we may say that for n pairs of these chambersThis takes care of the straight pressure additions and subtractions. Forother functions we may write,

AV-d=fAp where JAp may be any function of Ap such as Ap log Ap etc. Thisis accomplished by putting a shaped displacer in the chamber 20 or 22 asin Fig; 3: so that the weight of fluid dis- APAL T r( g" 1 1 2 2) and bymaking AP=10g Apr-l-log- A102 Therefore if the pressure gauge H; has alog scale it will read the product of A101 and A102, etc.

From the foregoing description of the invention it is evident that thesystem of measuring or totalizing fluid pressures is simple and accurateand is useful for giving constant and direct readings ofair fluidpressures in any fluid pressure system, including the total pressure ofa plurality of fuel or air supply linesto industrial furnaces orthe likein terms of direct or derived quantities.

Although one embodiment ofthe invention has been herein illustratedand'described, it will be evident to those skilled in the art thatvarious modifications may be made in the details of construction withoutdeparting from the principles herein set forth.

I claim: I

1", The system of totalizing" and subtracting fluid pressures comprisina weigh beam having. a plurality of liquid-containers supported on oneend thereof and having apneumatic balancer acting upon theb'eamat theother end thereof, fluid containers stationarily mounted and connectedto said first named containers by a flexible conduit at .thebottom ofsaid con t'ainers to establish communication of the fluids in saidcontainers, said second named containers having connection above theliquid level with sources of variable pressure and a pressuregaugeconnected to aid pneumatic. balancer for indicatin the total valueof the pressure of. said variable pressure sources.

2. A device for totalizing fluid pressures comprising a weigh beammounted on a fulcrum and having a plurality of liquid receivingcontainers mounted on said beam at one side of said fulcrum and apneumatic balancer comprisin a cylinder having a diaphragm adapted forconnection to a source of supply of compressed air of substantiallyconstant pressure, said diaphragm having a thrust member acting on saidweigh beam at the opposite side of said fulcrum from that which is actedupon by said fluid receiving containers, a valve in said cylinder andactuated by said diaphragm to control the admission ofair pressure tosaid chamber when the diaphragm moves in one direction from a positionof beam balance and to vent the cylinder to the atmosphere when thediaphragm moves in' the opposite direction from said position of beambalance, and a plurality of containers stationarily and independentlymounted with respect to said beam-mounted liquid receiving containers,each of said stationarily mounted containers being connected byfi'exible tubing to aliquid receiving container on said beam, a liquidinsaid stationary containers, means for applying diiferent pressures tothe respective stationary containers whereby liquid may be reversiblydisplaced from the several stationary containers to the liquid receivingchambers in response to variations in pressure, whereby the weigh beamis unbalanced by changes in total weight of" liquid acting on said beamand whereby the pressure actin on said pneumatic balancing diaphragm iscaused to be adjusted to a value at which the beam is restored to itsbalanced positionand a pressure gauge connected to said pneumaticbalancer to indicate by the value of pressure therein the total value ofthe pressures supplied to the re-- spective stationary containers.

3. A device for algebraically totalizing a plurality of fi'uidpressurescomprising a weigh beam mounted on a fulcrum, a plurality of liquidreceiving members suspended from said beam at one side of said fulcrum,a pneumatic balancer mounted to act on said beam at the other side ofsaid fulcrum, said balancer having a valve disposed to be actuatedthereby for controlling the a'dmissionand' exhaust" of a fluid pressureto and: from said balancer in response to the development of anunbalance between the total weight of liquid in said fluid chambers andthe force exerted bysaidbalancer on said beam, a

plurality ofchambers supported independently of said Weigh beam,flexible tubing connecting each of said". latter chambers to a fluidreceiving chamber suspended from said weigh beam, whereby displacementof fluid between the several independently mounted chambers and saidweigh beam liquid receiving chambers may be effected in responsetovariable pressures being applied to said independently mountedchambers and' whereby said: valve is actuated to develop! a pressure'insaid balancer that will restoresaid Weigh beam to a condition of balancewithv the'tot'a'l weight-of liquid in the charm-- bers" suspended" fromsaid weigh beam and apressuregauge connected to said pneumatic balancerto indicate by the value of pressure there in" the total value ofthe-pressure supplied to the respective: stationary containers.

A'IIZJERED A. MARKSONL (References on following page) REFERENCES CITEDNumber The following referemces are of record in the 2 2 file of thispatent: 3

UNITED STATES PATEN'I'S 5 Number 7 Name Date Number 703,753 Amdt July 1,1902 437,292 751,296 Jones Feb. 2, 1904 583,401 1,638,101 Roucka. Aug.9, 192': 611,179

Ziebolz Dec. 3, 1940

